The legendary Euclid by Richard Campbell
THE Euclid S-7 was a highly successful machine, occupying a fairly unique space in the history of the evolution of the motorscraper.
It was produced in two countries and had an uninterrupted production life of 18 years.
During its life it had only one really serious competitor until the elevating scraper, with its ability to work alone without the aid of a push tractor, made it unviable for most contractors.
Originally introduced in 1954, the S-7 was powered by a General Motors 4-71 diesel rated at 143 flywheel horsepower. This was upgraded to 148 horsepower in later models.
Initially a direct drive Fuller 5CB650 transmission with air assisted clutch was fitted but with the higher horsepower available an Allison CLT3341 4-speed powershift transmission was made standard which gave the 11.8 ton S-7 a top speed of around 28 miles an hour.
Legally roadable just about everywhere, the S-7 quickly created a niche for itself and the machine enjoyed worldwide sales. Such was the demand for the S-7, Euclid Great Britain set up a production line in 1955 to produce the machines in Britain for the European and Commonwealth markets.
The British machines were practically identical to the machines produced in the USA except for the engine, which in early British versions was a Leyland AU600 rated at 147 flywheel horsepower, and the electrical system which was supplied by Simms.
From 1961 the Leyland engine was replaced by a General Motors 4-71 diesel.
The S-7 was considerably easier to operate than many other small scrapers of the day with all-hydraulic control of the bowl, apron and roll-out ejector. The only cable on the machine was attached to the apron actuating arm.
Steering was also all-hydraulic using Euclid’s patented ‘follow up’ system.
Air brakes were fitted to both axles although they seldom worked once in operation, most operators preferring the bowl to stop on the job !
The bowl was rated at 7yd3 struck and 10yd3 heaped, which made it an ideal sized machine for small subdivisional jobs, county road construction and landscaping.
The entire machine resembled one of Euclid’s larger machines but in miniature !
Competition came from several manufacturers – the Allis Chalmers TS-160, Curtiss-Wright CW27, Michigan 110 and the Le Tourneau-Westinghouse model D which was by far and away the S-7’s biggest rival.
It is interesting to note that Caterpillar never offered a machine in this size and configuration until the 611 came along in the 1990s – possibly indicative of just how well Euclid and Le Tourneau-Westinghouse dominated this size class at the time.
By the early 1970s the elevating scraper had well and truly captured the small scraper market and Euclid, in a bid to be competitive, mated a Hancock 12 cubic yard elevating scraper to an S-7 tractor unit creating the S-12E.
Sales of this machine were not very high – Le Tourneau-Westinghouse had already captured a good deal of business by concentrating on elevating scrapers in the mid 1960’s and Euclid (now Terex) was losing ground to other manufacturers as well.
The S-7 was discontinued in 1972 and replaced by the S-11E – an all new elevating scraper.
The NZ Connection
There were 23 Euclid S-7’s imported into New Zealand by agent Clyde Engineering between 1956 and 1969 – 13 of British manufacture and 10 from the USA.
These saw service all over New Zealand and on many varied jobs from airport construction to school site development.
Users of the type included Ian Martin Ltd, Dornbusch Bros, Te Pohue Contractors, K.J.McMillan, Beattie Bros, Gold Coast Contractors, Street Bros and numerous others.
Even after their tractor units had worked out their useful life, many scraper bowls got a new lease of life as towed scrapers. Small hydraulic scrapers of this size are remarkably useful tools. It has been a while since the author last saw a complete S-7 and I would be very interested to know just how many are left in operational condition.
Brief Specifications – Euclid S-7 – (mid production USA build 4UOT model)
Engine: GM 4-71 4-cylinder inline diesel rated at 148 hp
Transmission: Allison CLT3341 4-speed powershift
Standard Tyre: 18.00 x 25
Brakes: Expanding shoe
Steering: Hydraulic orbitrol valve, twin cylinder
Length: 29’ 10”
Height: 8’ 5”
Wheelbase: 17’ 10”
Capacity: struck 7 cubic yards
heaped 10 cubic yards
Operating Weight: 26,500 lb (11.8 tons)